Medical practice chair with adjustable seat frame



July 6, 1954 MEDICAL PRACTICE CHAIR WITH ADJUSTABLE SEAT FRAME OriginalFiled July 2, 1946 4 Sheets-Sheet l INVENTOR.

Norma/z .5 la zerbacfi W Hi5 Avior/26y N. E. LAUTERBACH 2,682,916

' y 6, 1954 N. E. LAUTERBACH 2,682,916

MEDICAL PRACTICE CHAIR WITH ADJUSTABLE SEAT FRAME Original Filed July 2,1946 I 4 Sheets-Sheet 2 INVENTOR. /V0 Mia/1 E. Lauzerbach July 6, 1954N. E. LAUTERBACH MEDICAL PRACTICE CHAIR WITH ADJUSTABLE SEAT FRAME 4Sheets-Sheet 5 Original Filed July 2, 1946 Fig, 3

INVENTOR. Norman 5 Lauzerfiaclz W #12: Affomey July 6, 1954 MEDICALPRACTICE Original Filed N. E. LAUTERBACH CHAIR WITH ADJUSTABLE SEATFRAME July 2, 1946 4 Sheets-Sheet 4 o ,Q'x N Fa INVENTOR. A orman E.Lauzerbach Hz'; Attorney Patented July 6, 1954 MEDICAL PRACTICE CHAIRWITH ADJUSTABLE SEAT FRAME Norman E. Lauterbach, Newark, N. Y., assignorto Ritter Company, 1110., Rochester, N. Y., a

corporation of Delaware Original application July 2, 1946, Serial No.680,983. Divided and this application October 1, 1949, SerialNo.-119,094

9 Claims.

This invention relates to chairs of the variety adapted for use by themedical profession during examinations, treatments and minor operations,one object of the invention being to provide an improved chair of suchcharacter having a more adjustable, convenient, and efficientconstruction.

Another object is to provide a chair of the above character having head,back, arm, and foot rests adjustable to and from positions 1yingsubstantially in the plane of the chair seat, for converting the chairinto a substantially fiat,

' table-like support.

Another object is to provide such a chair having an adjustable seatframe which may be tilted throughout a range of positions relative tothe top of the elevating column.

Another object is to provide an efficient and easily workable means oflocking said seat frame in the desired tilted position. I

This application is a division of my copending application, Serial No.680,983, now Patent No. 2,558,143, filed on July 2, 1946, Medical Practice Chair, to which reference may be had for parts disclosed but notclaimed herein.

To these and other ends the invention resides in certain improvementsand combinations of parts, allas will be hereinafter more fully de--scribed, the novel features being pointed outin' the claims at the endof the specification.

In the drawings:

Fig. 1 is a side elevation of a chair embodying the'present inventionand arranged to support a patient in an uprightsitting position;

Fig. 2 is a top plan view of the chair arranged horizontally withportions of the seat broken away to disclose parts of the mechanism;

Fig. 3 is an enlarged top plan view of the seat frame and associatedmechanism partly in section and partly broken away;

Fig. 4 is an enlarged fragmentary view of certain details of themechanism shown in Fig. 3;

Fig. 5 is a fragmentary side elevation of the seat frame, partly brokenaway to show a looking means;

Fig. 6 is a sectional view on line 20-20 in Fig. 5, and

Fig. 7 is a sectional view substantially along the line 'l'! in Fig. 4.

The preferred embodiment of the invention herein disclosed, by way ofillustration, comprises a chair having a circular base Mi, Fig. 1,supporting an electric motor 4| and a housing 42 for hydraulic mechanismfor raising and lowering a chair supporting column 43' which is mountedfor rotation also in the housing, as well understood in the art. At 44is ent invention.

The chair column carries at its top a generally v circular supportinghead 4 6 formed with bearings 41, Figs. 2 and 3, for trunnions 48 bywhich a seat frame 49 is supported for tilting movement on the chairbase. Means are provided, as hereafter described, for releasably lockingthe seat frame in adjustably tilted positions. The seat frame 49 is agenerally rectangular, hollow frame, as shown, on which the back rest,arm rests and leg and foot rests, shown generally at 83, 85, 81 and 89,respectively (Fig. 1 are supported in connected relation for movementsimultaneous- 1y to difierent adjusted positions.

The rear of the seat frame is formed with an integral, hollow, box-likeportion indicated generally at 9| (Fig. 3), with which the back rest ispivotally connected. This portion BI comprises spaced, rearwardlyextending walls 93 (Fig. 1), the front and lower sides of which arecurved substantially in 'a semi-circle as shown in Figs. 1 and 5. aspindle 95 (Fig. 1) pivotally supporting an irregularly shaped member(not shown) forming the base portion of the back rest. Fixed on andextending upwardly from this irregularly shaped member is a post 91(Fig. 1) slidably received in a bearing in a member 99 having in itsrear face an undercut or dovetailed vertical groove (not shown) slidablyreceiving a similarly shaped tongueon a member llll. Member IIH isprovided with a clamp (not shown) operated by a handle I83 for lockingthe tongue in a vertical position in the grooves in member 99. Member His provided at its upper end with lugs I05 between which is pivotallysupported a depending arm I87 secured to the rear side of asubstantially rectangular, padded back rest [09 shaped to conformsubstantially to the patients back.

As pointed out in my above copending application, Serial No.' 680,983,when the back rest is tilted backwardly and lowered to a table-likeposition, back rest pad IE9 is moved towards the seat to maintain anormal distance therebetween. This is an important feature for,otherwise, the pad [09, during such movement, would slide up thepatients back, uncomfortably disarranging his clothes, and leaving a gapbetween it and the seat.

Each arm rest comprises a frame Ill hav- Walls 93 are formed withbearings and r r ing at its lower forward end a trunnion 5! (Fi 3)journaled in the side of the seat frame 49, as hereafter described andas described in my said copending application. The upper rear end H3(Fig. l) of arm rest frame iii is pivotally connected at l i5 with armsI ll extending forwardly from the part 9% of the back rest which slideson pivoted post 91.

Trunnions 5| are pivotally supported in a hearing in the side of theseat frame A9 comprising an outer boss H9 (Fig. 3) and an inner boss l2!(Fig. 4). Trunnions 51 extend inwardly beyond inner bosses l2! and areconnected to one end of a pair of strong coiled springs I23 (Figs. 3 and4) which are connected at the opposite ends thereof to the seat frame bybolts 125 (Fig. 3). Springs I23 serve to counteract the weight of thepatient against the back rest and to assist in lifting the back rest andpatient to a sitting position. Trunnions 5% are each also preferablyconnected to the leg and foot rest supporting mechanism by means of alever l2! (Fig. 4) keyed thereto which in turn is connected to the legrest frame mechanism by a pair of bars or links [29 (Figs. 3 and a).Links i29 are connected at the forward ends thereof to a lever [3| keyedto a shaft 533 (Fig. 3) mounted for rocking movement at its oppositeends in bearings (not shown) in the sides of the seat frame. Mounted torock independently on shaft I33 is a sleeve I35 (Fig. 3) to the oppositeends of which are fixed a pair of spaced arms 13? (Fig. 3) having upperends of gooseneck shape to avoid interference with the front end of theseat frame. Arms l3? form part of a hinged frame of rigid constructionfor supporting the leg and foot rests, as described and claimed in mycopending application, Serial No. 119,095, Medical Practice Chair withAdjustable Leg and Foot Rest Supports, now Patent No. 2,612,940, grantedOctober '7, 1952.

As explained above, the seat frame is supported for tilting movement onthe top 46 of the elevating column 43 and the armrest structure isutilized in part for controlling means for locking the seat frame inadjustably tilted position on the column. Such means preferablycomprises a sleeve 55 keyed on the inner end of the trunnion 5! of oneof the arm rests (Fig. 4) inwardly of lever :21, as shown in Fig. 4.Fixed in this sleeve are one or more radially extending pins 52 receivedin inclined slots or notches 53 in a cap 55 rotatably and slidablymounted on the sleeve so as to be controlled for movement bothconcentrically and axially of the sleeve. The cap 5 5- has a strap 55clamped thereto and forming part of the end of an angular lever 56,Figs. 3 and 4, extending rearwardly and upwardly along the under side ofthe adjacent arm rest. Lever 55 has a projecting portion or lug i39(Fig. 4) which projects outwardly through a rectangular opening, as atM] (Fig. 4), formed in strap 55 for holding one end of said strap inposition on said lever while allowing the opposite end thereof to betightened by a screw i i-3 (Fig. l). Set concentrically in the cap is athreaded plug 52' of hardened steel having therein a socket 58 for thereception of a rounded and hardened bearing surface 59 at the left endof a thrust element or rod fill, as seen in Fig. 3. This end of the rodis thus supported concentrically with the trunnion of the arm rest, soas to be undisturbed by its tilting movement on the seat frame, and itwill be seen that the swinging of lever 56 in either direction 4 rotatescap 54 whose inclined slots 53 move the cap axially of the sleeve topress its plug 51 against rod 65 to thrust it longitudinally. Rod 56thrusts at its opposite end against the resistance of spring-actuatedmeans for operating the locking means controlling the tilting movementof the seat frame on the elevated column of the chair base, as hereafterdescribed. It will also be noted that lever 55 is mounted on cap as andis caused to follow the movements of the arm rests, so as to beconveniently and easily located for actuation by the operator of thechair. Sleeve 59 is keyed to trunnion 5| which in turn is keyed to thearm-rest frame I l I so that the arm rest cannot rotate relative to theseat frame without the corresponding rotation of trunnion 5i and sleeve55). While cap 5A, to which lever fit is fixed, is rotated relative tosleeve 53 for releasing the seat-frame locking mechanism, cap 5:3 iscaused to rotate with trunnions 5i as the arm rests rotate relative tothe seat frame. That is, pins 52 on sleeve engage the slots in cap 53,and as the sleeve 5%] and trunnions 5! are rotated, cap 54 will eitherbe rotated therewith, or cammed axially along sleeve 58. However, thecamming action of cap St is opposed by the resistance of spring 63 andof the seat-frame locking mechanism, whereas the only resistance to therotation of cap 54 with sleeve 58 results from the engagement betweenrounded bearing surface 5d, ofthrust rod 69, and socket 58 of plug 51.As the above resistance to rotation is considerably less than the aboveforces resisting the camming movement of cap 54, cap 5% is readilyrotated with sleeve 59, trunnion 5i and arm rest frame Ill, as the armrests are raised and lowered relative to the seat frame.

Thrust rod 5E has at the opposite end thereof a rounded and hardenedbearing surface 61 which is seated in a socket {52 in a lever 63 pivotedat 6 5 on a lug tfion the head of the elevating col umn. The rod socketE2 is located concentrically with the axis of the seat frame trunnionst8, so that the rod is unaffected by tiliting-movements of the seatframe on the column. At is a coiled compression spring having one endseated in a recess in lever 63and the other end seated in a recess inanextended portion 67 of the adjacent column bearing 47. One function ofthis spring is to press lever 83 against rod 5!) and normally thrust itagainst plug 5? in cap 54.

1e means for releasably locking the seat frame in its adjustabletilted-positions on the base comprises, preferably, a block 38 (Figs. 3,5, and 6) pivotally supported by trunnions 59 having hearings in lug 65and a cooperating lug 'iil spaced therefrom on the head of the column.This pivoted block "53 is formed with a bearing opening which slidablyreceives a spindle 'H connected with the chair frame, as hereafter described. Block 68 has a slot '52 extending inwardly to its spindlebearing to provide for compressive clamping of the block around thespindle to lock it thereto. Such locking compression of the block ispreferably accomplished by means of a rod 73 sliding longitudinally in abore in lug 65 with one end bearing against lever 53 and the otheragainst the adjacent side of the block. The opposite side of the blockis supported by a short stop rod M fixed in lug l6.

Locking spindle "H is carried by a head 15 formed on or otherwisesecured to the top of the spindle and pivoted on a spindle is carried inlugs, llprojecting-inwardly from an abutment 18 on the seat frame. Acoiled compression spring [9, carried by an adjustable screw 80, on

It will be evident from this construction that.

the pressure of spring 66 against lever 63 normally'thrusts rod 13longitudinally to compress block 68 into locking engagement with thespindle carried by the seat frame so as to lock the latter in adjustedposition. Lever 56 may be rotated through a slight angle, however, tocam cap 56 axially of sleeve 59, as previously explained, and therebythrust rod 60, against lever 63 and thus release block 68 to relieve itslooking action on the seat frame spindle H, thus freeing the seat framefor tilting movement as long as lever 56 is held in such position.During such tilting movement of the seat frame, the

thrust rod 60 is'turned bodily about its end 6| concentric with thetilting axis of the frame, so as not toaffect the operation of the framelocking means, notwithstanding the location of the other end of thethrust rodin eccentric relation to such pivotal axis The inventionsupplies an improved and advantageous arrangement for locking the seatframe in adjustably tilted position on the elevating column. Suchmovement of the seat frame relative to the elevating column iscontrolled by a locking lever uniformly positioned along the rear sideof one of the arm rests so as to be easily located by the operator withminimum attention and effort.

It will thus be seen that the invention accomplishes its objects andwhile it has been herein disclosed by reference to the details of apreferred embodiment, it is to be understood that such disclosure isintended in an illustrative, rather than a limiting sense, as it iscontemplated that various modifications in the-construction andarrangement of the parts will readily occur to those skilled in the art,within the spirit of the invention and the scope of the appended claims.

I claim:

1. A chair comprising a base, a frame mounted for tilting movement onsaid base and provided with a seat, a back rest pivotally and slidablymounted on said frame, arm rests pivotally connecting said frame andback rest for movement of the arm rests with said back rest, means forlocking said frame in different tilted positions, and an operating leverfor said locking means connected and movable with one of said arm restsduring the pivotal movement of the arm rests relative to said frame.

2. A chair comprising a base, a seat frame mounted on said base fortilting movement about one axis, a back rest pivotally and slidablyconnected with said frame, arm rests connected with said back rest andpivotally connected with said frame for movement about an axis spacedfrom said first axis, locking means for securing said frame inadjustably tilted position on said base, actuating means for saidlocking means having a part concentric with each of said axes, and alever for operating said actuating means connected and movable with oneof said arm rests during the pivotal movement of the arm rests relativeto said frame.

3. A chair comprising a base, a seat frame mounted on said base fortilting movement about one axis, a back rest pivotally and slidablyconnected with said frame, arm rests connected with said back rest andpivotally connected with said frame for movement about anaxis spacedfrom said first axis, means for locking said frame in adjustably tiltedposition on said base, and means for operating said locking meanscomprising a thrust element having opposite end portions locatedsubstantially on said axes, respectively.

4. A chair comprising a base, ,a seat frame mounted on said base fortilting movement about an axis, a back rest slidably connected With saidframe for pivotal movement about an axis, arm rests movably connectedwith said back rest and connected with said frame for pivotal movementabout an axis, means for locking said frame in adjustably tiltedposition on said base, actuating means for said locking means having aportion located substantially on the tilting axis of said seat frame, athrust element having one end connected with said portion and the otherend located substantially on the pivotal axis of one of said arm rests,and means comprising a lever connected and movable with said one of saidarm rests during the pivotal movement of the arm rests relative to saidframe, said lever being movable relative to said arm rest for movingsaid thrust element and operating said locking means in any adjustedposition of said rests and seat frame.

5. A chair comprising a base, a seat frame mounted on said base forpivotal movement about an axis, a back rest pivotally and slidablyconnected with said frame, an arm rest connected with said back rest andconnected with said frame for pivotal movement about an axis, means forlocking said frame in adjustably tilted position on said base and havingan operating portion located substantiallyon said frame axis, a thrustrod connected at one end with said portion and having its opposite endlocated substantially on said arm rest axis, cam means on said arm restaxis for moving said rod longitudinally of said axis, and a levermovable with said arm rest during the pivotal movement of the arm restrelative to said frame, said lever being movable relative to said armrest for actuating said cam means and operating said frame lookingmeans.

6. A chair comprising a base, a seat frame mounted on said base fortilting movement about an axis, a back rest pivotally and slidablyconnected with said frame, arm rests movably connected with said backrest and connected with said frame for pivotal movement about an axis,means for locking said frame in adjustably tilted position on said base,actuating means forsaid locking means having a lever movably mounted onsaid base, one end of said lever being located substantially on thetilting axis of the seat frame, and a thrust element having one end inengagement with said end of said lever, the other end of said thrustelement being located substanitally on the pivotal axis of one of saidarm rests.

7. A chair comprising a base, a seat frame mounted on said basefortilting movement about an axis, a back rest pivotally and slidablyconnected with said frame, arm rests movably connected with said backrest and connected with said frame for pivotal movement about an axis,means for locking said frame in adjustably tilted position on said base,actuating means for said locking means having a lever pivoted on saidbase, a spring for moving said lever in one direction for actuating saidlocking means, one end of said lever being located substantially on thetiltingi axis'vof the seat frame, and a thrust elementv having one endin engagement with said end-70f said lever for moving said lever in theopposite direction to release said locking means, the other ,end of saidthrust element being 10- catedcsubstantialiy on the pivotal axis of oneof said arm rests.

8. A chair comprising a base, a seat frame mounted on said base forpivotal movement'about an axis, a back rest pivotally and slidablyconnected with said frame, an arm rest pivotally connected with saidback rest and connected with said frame for pivotal movement about anaxis, clamping means for locking said frame in adjustably tiltedposition on said base, actuating means for said clamping means having apart located substantially on the tilting axis of said seat frame, and athrust element having one end connected with said part and the other endlocated substantially on the pivotal axis of one of said arm rests.

9. A chair comprising a base, a seat frame mounted on said base forpivotal movement about an axis, a. back rest pivotally andslidablyconnected with said frame, an arm rest pivotally connected withsaid back-rest and connected with said frame for pivotal movement aboutan axis, an elongated element pivotally attached to and movable withsaid seat frame; a clamping means on said base for releasably engagingsaid element for locking said frame. in adjustably tilted posi tion onsaid base, actuating means for said clamping means having a part locatedsubstantially on the tilting axis of said seat frame, and a thrustelement having one end inengagement with said part and the other endlocated substantially on the pivotal axis of one of said arm rests.

References Cited in the file of this patent UNITED STATES PATENTS ma jaw

